please help me finish part a + part b, thanks. no excels will more better

a) in the first trading day of 1998, Hang Seng Index closed at 10680.60, while in the last trading day of 2017, it closed at 29919.15. What is the average annual growth rate of Hang Seng Index in this 20 year? (5 marks) b) The following yield curve is observed of the US Treasury securities on 28th October 2019: Maturity (Year) Yield Rate (%) 1.60 1.64 1.65 Suppose the pure expectation theory is correct. Forecast the expected one year yield rate of one year later and of two years later respectively